It is common knowledge that most oil filters of the canister type can not be removed by hand alone. This condition is due to the tightness required to seal an oil filter to the engine block in order to prevent oil leakage under pressure. Also in cases where the automobile has recently been driven the engine oil will heat the oil filter canister to the point that an individual may suffer sever burns in grasping the oil filter canister by hand.
As can be seen by reference to the following U.S. Pat. Nos. 4,552,040; 4,266,452; 4,643,053; 3,385,141; 4,964,330; 5,065,648; and 5,090,274; the prior art is replete with myriad and diverse oil filter wrenches and devices designed to assist in the removal or installation of oil filters.
Most oil filter wrenches that can be adjusted to fit various size oil filter canisters require a large area in which to extend the handle in order to obtain the necessary leverage to tighten the device around the oil filter canister. Likewise, the handle must remain extended to apply the torque required to tighten or loosen the oil filter canister.
With the advent of smaller automobiles and the more compact compartments for automobile engines the area for extending the handle on the aforementioned oil filter wrenches has been greatly reduced and in many instances the clearance necessary to extend the handle is no longer available. U.S. Pat. No. 4,552,040 is an example of an oil filter wrench with an extended handle.
Other devices, generally referred to as housing-type devices, do not require extending a handle; however, most of these devices are not adjustable and will fit only one size oil filter canister as exemplified by U.S. Pat. No. 4,266,452. There is disclosed four types of wrenches with adjustable mechanisms as found in U.S. Pat. Nos. 3,385,141; 4,964,330; 5,065,648; and 5,090,274. While the four aforementioned prior art devices are more than adequate for the purpose for which they were designed, they are deficient in the following manner.
As to U.S. Pat. No. 3,385,141 one embodiment requires that the oil filter canister be loosened prior to slipping the housing-type device over the oil filter canister. Utilizing this device requires two steps. The first step is to loosen the oil filter canister by one means or another and the second step consists of placing the housing-type device over the previously loosened oil filter canister for the final removal of the oil filter. A stated objective of the device is to protect the user from oil dripping over the top of the filter. It is obvious that the above embodiment is for protection from dripping oil not for the initial removal of the oil filter canister from the engine block. Another embodiment of the device has three independent toothed dogs pivotally mounted on pins with support brackets attached to the inside of the housing. This housing means is more than adequate to accept different size oil filter canisters. However; this embodiment recognizes the difficulty in removing an oil filter canister by hand and; therefore, provides a hexagonal lug attached to the housing to aid in the removal of the oil filter canister by utilizing a hand wrench to be attached to the lug.
As to U.S. Pat. No. 4,964,330 the housing mechanism is designed to fit over various size oil filter canisters by employing several commonly recognized adjusting mechanisms to secure the housing means to the oil filter canister. The method for installing and removing an oil filter using the subject device consists mentioned housing mechanism. The difficulty in removing an oil filter by utilizing one's fingers is recognized in the application by stating that a small pry tool may be used to loosen a stuck or over tightened oil filter. In addition, should the automobile have recently been driven, the finger engagement means may also be extremely hot as the device is designated to remain attached to the oil filter canister during driving operations.
The device described in U.S. Pat. No. 5,065,648 is capable of grasping various size oil filter canisters; however, in order to apply leverage a wrench handle must be attached to the device. The handle protrudes outwardly from the grasping mechanism and; therefore, a relatively large amount of clearance is required to manipulate the oil filter wrench. The wrench appears to be most useful for a motor cycle engine as mentioned in the patent.
An oil filter changing device was granted U.S. Pat. No. 5,090,274. While the device is designated to fit various size oil filter canisters it also requires a handle be attached to the instrument to gain leverage in changing an oil filter canister. The mechanism for attaching the device to the oil filter canister protrudes outwardly from the oil filter canister. This condition; therefore, requires a considerable amount of space to accommodate the separate handle that must be affixed to the device for leverage.
From reviewing the prior art it is evident that there is lacking an oil filter canister tool suitable for extremely confined areas that provides sufficient means for grasping the tool by hand in a manner to maximize the leverage and torque associated with wrist action aided by arm strength and shoulder power for the removal and installation of an oil filter. Utilization of this procedure without the necessity of a separate handle is the stated object of the present invention. The small size and air cooled aspect of the device are additional benefits that maximize the usefulness of the device.